Front end loader



June 27, 1967 E. c; BROWN FRONT END LOADER 5 Sheets-Sheet 1 Filed Aug.9, 1965 INVENTORS: EDWIN C. BROWN ROY D. BROWNELL -lune 27, 1967 E. C.BROWN FRONT END LOADER 5 Sheets-Sheet 2 Filed Aug. 9, 1965 FIG, 2B

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June 27, 1967 E. c. BROWN 3,327,880

FRONT END LOADER Filed Aug. 9, 1965 4 3 Sheets-Sheet 5 INVENTORS: EDWINC. BROWN ROY DBROWNELL AT T'.YS

United States Patent O 3,327,880 FRONT END LOADER Edwin C. Brown and RoyD. Brownell, Aurora, Ill., as-

signors to Baldwin-Lima-Hamilton Corporation, Lima, Ohio, a corporationof Delaware Filed Aug. 9, 1965, Ser. No. 478,236 11 Claims. (Cl.214-770) This invention relates to a front end loader, and moreparticularly to Ia front end loader which may be either Wheel orcrawler-mounted and equipped with power means for providing horizontalforward crowding at the ground line while utilizing a single powersource to raise the excavating bucket t-o maximum elevation.

In conventional front loaders, the forwardly-opening excavating bucketis usually moved forward adjacent the ground line by advancing thetractor or crawler itself, and in instances where the bucket may -bemoved forwardly by separate power means, complicated support mechanismrequires several operations and the utilization of several power meansfor raising the bucket to maximum elevation.

We have discovered that a front end loader equipped with an inner boomand an outer boom in jackknife relation may be mounted upon a vehicleand power means provided whereby actuation of the power means provides ahorizontal forward crowd of the excavating bucket while at t-he sametime permitting rapid elevation of the bucket to its maximum elevationthrough the use of single power cylinder means. This is accomplishedthrough the use of two power cylinders which are controlled foroperation in unison for providing the forward horizontal crowdingmovement while only one of the power means is required for rapidlyswinging the bucket to a maximum elevation.

A primary object, therefore, is to provide a front end loader, eitherwheel or crawler-mounted, having an inner and outer boom in jackkniferelationship, with power means effective for moving an excavating bucketin a forward, horizontal crowding line, without moving the loader whileat the same time permitting -rapid elevation of the bucket to maximumheight in a `single operation. A further object is to provide in such astructure hydraulic circuit control means in which the discharge fromone power cylinder feeds into the input side of a second hy-` drauliccylinder whereby the piston rod means of the cylinders are movedsimultaneously and in unison to prov-ide horizontal forward crowdingmovement at the ground line. A still further Iobject is to provide insuch a structure means by which a single one of such power cylindermeans may be actuated for raising the bucket to maximum elevation. Yetanother object is to provide in such a structure a parallelogramarrangement of the outer boom with a rigid tension member, both beingmounted upon an inner boom pivotally anchored at its lower end on 'thebase of the machine chassis, and with the excavating bucket supportedupon said outer boom. Another object is to provide a vehicle in whichinner and outer booms are actuated by hydraulic cylinders which are sorelated to each other that -controlled and simultaneous piston rodmovement in leaning the inner boom outward and hinging the outer boomaway from the inner boom produces horizontal movement at the lower endof the outer boom where the bucket is attached and permits below groundexcavation by forward tilting of t-he inner boom. Other specific objectsand advantages will appear as the specification proceeds.

The invention is shown, in illustrative embodiments, by the accompanyingdrawings, in which:

FIGURE l is a perspective view of a wheel-equipped vehicle or tractorequipped with apparatus embodying our invention; FIG. 2A, a side view ofthe apparatus 3,327,880 Patented June 27, 1967 ice shown in FIG. 1, withthe excavating bucket raised to elevated position; FIG. 2B, a portion ofthe structure shown in FIG. 2A but showing the bucket in lowered,crowding position; FIG. 3, a schematic view showing the hydrauliccontrol system for operating the power .cylinders separately andselectively and also simultaneously and in unison; FIG. 4A, a side viewin elevation of the struct-ure shown in FIG. `2A with the bucket inelevation but with the mechanism mounted upon the turret structure of acrawler-type of vehicle; and FIG. 4B, a portion of the structure shownin FIG. 4A but comprising the apparatus in lower, crowding position.

In the illustration given in FIGS. l, 2A and ZB, 1l) designates awheel-equipped vehicle of the truck or tractor type. To the brackets 11mounted on the forward end of the vehicle are pivotally secured theinner boom members 12. The inner boom members are connected at theirtops by a pivot pin 13, The two pivoted members 12 comprise a forwardtiltable support or mast, which is referred to herein as the inner boom.

An outer boom 14 is provided by two spaced members connected by a pivot15 to the inner boom members at a point below `the upper pivot 13. Theouter boom 14 is shown provided with a rigid tension member or link 16also pivotally carried at the top of the inner boom 12 by the pivot 13.At the 'bottom of the link 16 is an inverted, U-shaped connector 17pivotally mounted by a pin 18 upon a pair of bell crank members 19.

A conventional forwardly-opening excavating bucket 20 is supported uponthe lower end of the boom members 14, the bucket being pivotally carriedupon the arm 21 mounted by pivot 22 upon the outer boom 14. The bucketmay be supported and operated by conventional support mechanism such asthe pivot links 23 and support links 24. A power cylinder 25 istrunnion-mounted and supported upon the bell crank members 19 and thepiston 26 is elfective for positioning the excavating bucket forcrowding, lifting and dumping, as illustrated in the drawings. Sincesuch structure is conventional and well known, a further detaileddescription is believed unnecessary.

For operating the inner and outer boom members, we provide hydraulicpiston-equipped power cylinders together with control mechanism for theactuation of the cylinders. Two spaced cylinders 27 are pivotallysupported -at their inner ends to the standards 28 carried by thevehicle 10. The pistons of the cylinders are connected to the pivot rod15 which passes through the inner boom members 12.

Between the members 12 which comprise the inner boom, is mounted atrunnion 29 supporting a hydraulic cylinder 30 within bracket 29a. Forease of identification, the hydraulic cylinder 39 is referred to hereinas the crowd cylinder, and the two cylinders 27 are referred to as hoistcylinders. The piston of cylinder 3G is secured to a pivot ring 31engaging pivot pin 32 which passes through the members 14 of the outerboom.

Hydraulic control means are provided for causing the hoist cylinders andthe crowd cylinder to operate independently and in unison, thearrangement being such that, for a horizontal crowding movement, whichis illustrated in FIG. 2B, both cylinder means may be operatedsimultaneously to cause the actuating levers to move outwardly inunison, effecting the crowding Iaction illustrated in FIG. 21B. Further,with such structure, the crowd cylinder 30 may be left in the positionshown in FIG. 2A and the hoist cylinder 27 may be actuated alone tobring about the quick vertical movement to the position of maximumelevation shown in FIG. 2A.

Any suitable hydraulic control mechanism may be employed. In theschematic view shown in FIG. 3, the hoist cylinder 27 is shown withhydraulic liquid connections at 3 its two ends. Similar connections areshown for the doubleacting crowd cylinder 30. The valve body 33 of FIG.3 shows ow lines with a spool valve 54 mounted in one control recess anda spool valve 35 mounted in a similar control recess. Actuating levers3d and 37 are provided for manipulating the spools separately, and amember 38 is shown for operating the levers 36 and 37 simultaneously andin unison. The hydraulic fiuid is supplied from the pump 39 and thereleased fluid passes outwardly to a supply tank 40. Since the valvemechanism is old in itself, a further `detailed description is believedunnecessary.

In the above hydraulic valve mechanism, reciprocation in a verticalplane of either of the spool valves 34 and 35 diverts oil fro-m the pumpinto the end of the valve casing and toward which the spool valve ismoved, and oil flows from the pump through one end of the cylinder 27 or30 and from the other end of the cylinder li-ows back through the valvewhich is opened at the top of the valve by the grooved upper portion ofthe spool valve. When both the valves 36 and 37 are actuated by movingthe member 38 downwardly, the hydraulic uid flows similarly firstthrough the cylinder 27 `and thence back through the ow passages to thesecond valve 35 which, being similarly actuated, passes the fluid to thecylinder 30, and from the cylinder the oil returns passing through theupper groove of the depressed spool valve and thence outwardly to thetank.

The use of the valve is important in permitting the operation of thehoist cylinder and crowd cylinder separately, while also enabling thetwo cylinders to be operated simultaneously and with even movement bypassing the fluid in series so that the discharge from the hoistcylinder feeds the input side of the crowd cylinder. With the pistons ofthe two cylinder means moving in unison, an effective crowding actiontakes place, as illustrated in FIG. 2B, while utilizing the power ofboth of the cylinder means 27 and 30. Furthermore, as above stated, thecontrol permits utilizing the hoist cylinder 27 for bringing the outerboom in a single operation to its maximum elevation, as shown in FIG.2A.

Operation In the operation of the apparatus shown in FIGS. 1-3,inclusive, the power cylinder means 27 and 30 may be manipulatedseparately through the control mechanism shown in FIG. 3 to bring theexcavating bucket 20 to the position shown in solid lines in FIG. 2B. Toeffect forward crowding movement along the ground line, the control 38is moved downwardly to produce flow of the hydraulic fluid from the pumpto the two cylinders in series, with the fluid passing through the hoistcylinder 27 and the returning fluid from the rod end of the hoistcylinder 27 being diverted to the anchor end of the crowd cylinder 30,whereby the piston rods of both cylinders move outwardly simultaneouslyand in unison to effect the crowding movement shown in dotted lines inFIG. 2B. The bucket can then be swung by operation of the bucketcylinder 25 -to an upright position as illustrated in solid lines inFIG. 2A and the bucket, with its load elevated to the position shown inFIG. 2A by the action of the hoist cylinder 27. The bucket may then bedumped, as shown in dotted lines in FIG. 2A, by the action of cylinder25.

In the operation just described, it will be noted that both cylindermeans, namely, 27 and 30, are utilized in crowding action shown in`dotted lines in FIG. 2B, where the vehicle remains still and greatpower is required in the movement of the bucket through the engagedmaterial, while for elevation one of the two cylinder means, namely, 27,need only lbe used in effecting a rapid vertical elevation of thematerial.

In FIGS. 4A and 4B, the parts shown are substantially those alreadydescribed in connection with FIGS. 1, 2A and 2B, but such structure ishere mounted upon a turret 41 mounted upon a crawler-advancing mechanism42.

i The parts shown in FIGS. 4A and 4B are designated with the samenumerals followed by the letter "b as those employed in FIGS. 1, 2A and2B, and the operation of such parts is the same -as that heretoforedescribed in connection with FIGS. l, 2A and 2B.

While in the foregoing specification we have set out specific structurein considerable detail for the purpose of illustrating embodiments ofthe invention, it will be understood that such details may be varied bythose skilled in the art Without departing from the spirit of ourinvention.

We claim:

1. A front end loader, comprising a vehicle having an inner boompivotally mounted thereon and an outer boom pivotally mounted on theupper end portion of the inner boom in jackknife relation, said outerboom being provided at its lower end with a forwardly-opening excavatingbucket, power cylinder means mounted on said vehicle for actuating saidouter and inner boom, power cylinder means mounted on said inner boomfor actuating said outer boom, control means for actuating said powercylinders in unison to provide horizontal forward crowding of saidbucket and for separately actuating only one of said power cylindermeans for elevating said bucket to maximum elevation.

2. The structure of claim 1 in which the hydraulic uid ow actuating thecylinders is in series, with the discharge of one cylinder feeding theinput side of the second cylinder.

3. The structure as described in claim 1 in which the cylindersactuating the inner and outer booms are controlled by adjacent handlevers in a series hydraulic circuit in which the discharge from thefirst cylinder feeds the input side of the second cylinder, whereby thepiston rod movement of the cylinders is simultaneous and in unison toproduce substantially horizontal crowd.

4. A front end loader, comprising a vehicle, an inner boom pivotallyanchored at its lower end on said vehicle, power cylinder -means mountedon said vehicle for moving said boom on said pivot, an outer boompivotally mounted on the upper portion of said inner boom in jackkniferelation, a rigid parallel link pivotally mounted on the upper end ofsaid inner boom above the pivotal connection with said outer boom, abell crank at the lower end of said outer boom pivotally connecting saidouter boom and link, a forwardly-opening excavating bucket hinged upon4the lower end of said outer boom, power cylinder means carried by saidouter boom for tilting said bucket, and power cylinder means carried bysaid inner boom for actuating said outer boom, control means beingprovided for operating said power cylinder means actuating said boomsseparately and in unison.

5. A structure as described in claim 4 in which said parallel link ishinged to the top of said inner boom and above the pivotal connectionbetween said inner boom and outer boom.

6. A front end loader as described in claim 1 in which the vehicle iswheel-mounted.

7. A front end loader as described in claim 1 in which the vehicle iscrawler-mounted.

8. In a vehicle equipped at the front part thereof with fixed supports,'an inner boom pivotally anchored at its lower end on said supports, anouter boo-rn pivotally mounted on said inner boom below the upper end ofthe inner boom and in jackknife relation therewith said outer boom beingequipped at its lower end with an excavating bucket, power means mountedon said vehicle for tilting said inner boom forwardly and inwardly,power means mounted on said inner boom for moving said outer boomforwardly and inwardly, said booms being positioned relative to eachother so that simultaneous piston movement in moving the inner boomoutward and in moving the outer boom away from the inner boom, produceshorizontal movement at the lower end of the outer boom for crowdingmovement of said bucket.

9. The structure of claim 8 in which the two booms `are controlled `byhydraulic cylinders and hydraulic fluid control means cause flowselectively through the separate cylinders and flow selectively to bothcylinders for simultaneous movement 'of the two cylinder pistons inunison.

lil. A front end loader mounted upon a vehicle and comprising an innerand an outer boom in pivotally connected jackknife relation and with aforwardly-opening excavating -bucket mounted upon the lower end of theouter boo-rn, power means mounted on the lower end of the outer boom fortilting said bucket, power cylinders for moving said inner boomoutwardly and said outer boom upwardly, a rigid parallel link extendingbetween the upper end of the inner boom above the pivotal connectionbetween said inner and outer -booms and to a lower portion of the outerboom, a bell crank connecting said link in parallel with the lower endof said outer boom for maintaining horizontal bucket crowd withsimultaneous extension of the booms by said power actuating means.

11. In a front end loader vehicle, an inner boom pivotally mounted atits lower end of said vehicle and pivotally connected at its upper endwith a rigid parallel link, an outer boom pivotally mounted on saidinner boom below said connection with said rigid link and pivotallyconnected at its lower end with said rigid link, a forwardly-openingexcavating bucket hinged upon the lower end of said outer boom and saidlink, hydraulic power means mounted on said vehicle and equipped wit-h apiston rod pivotally engaging said outer boom at its point of connectionwith said inner boom, hydraulic power means carried by said inner boomfor actuating said outer boom, and control means for actuating saidpower cylinder means in unison for maintaining horizontal bucket crowdwith simultaneous extension of the booms by said power actuating means.

References Cited UNITED STATES PATENTS 2,965,253 12/1960 Poultier et al.214-138 3,120,315 2/1964 Johnson et al. 214-138 FOREIGN PATENTS 167,0632/ 1956 Australia.

HUGO O. SCHULZ, Primary Examiner.

1. A FRONT END LOADER, COMPRISING A VEHICLE HAVING AN INNER BOOMPIVOTALLY MOUNTED THEREON AND AN OUTER BOOM PIVOTALLY MOUNTED ON THEUPPER END PORTION OF THE INNER BOOM IN A JACKKNIFE RELATION, SAID OUTERBOOM BEING PROVIDED AT ITS LOWER END WITH A FORWARDLY-OPENING EXCAVATINGBUCKET, POWER CYLINDER MEANS MOUNTED ON SAID VEHICLE FOR ACTUATING SAIDOUTER AND INNER BOOM, POWER CYLINDER MEANS MOUNTED ON SAID INNER BOOMFOR ACTUATING SAID OUTER BOOM, CONTROL MEANS FOR ACTUATING SAID POWERCYLINDERS IN UNISION TO PROVIDE HORIZONTAL FORWARD CROWD-